scholarly journals Control strategy of optimal distribution of feet forces for quadruped robots based on virtual model

2021 ◽  
Vol 2113 (1) ◽  
pp. 012003
Author(s):  
Xinjie Chen ◽  
Yuegang Tan ◽  
Ruiya Li ◽  
Yecheng Mei
Keyword(s):  
Inverse Dynamics ◽  
Control Method ◽  
Lateral Force ◽  
Quadruped Robot ◽  
Optimal Distribution ◽  
Virtual Model ◽  
Distribution Method ◽  
Virtual Force ◽  
Target Values ◽  
Model Control

Abstract In order to improve the dynamic walking performance of quadruped robot, a control method of optimizing feet forces distribution based on virtual model is proposed. In the supporting phase, the virtual model control method is applied to solve the virtual force of the torso. Combined with the gravity of the center of mass (CoM), the distribution problem between the virtual force of the CoM and the feet forces of the supporting legs is transformed into a quadratic programming (QP) problem, which is solved by Gurobi to realize the optimal distribution of the feet forces. Similarly, the virtual force of the swinging leg is solved by using the virtual model, and the joints torques of the robot’s swinging legs are obtained by combining the inverse dynamics feedforward of the swinging legs. Through the simulation of quadruped robot’s trot gait walking by webots and vs2019, it is verified that this method can stabilize the robot’s attitude angles and body speeds near the target values. Compared with the feet forces distribution method that abandons the lateral force control, the application of this method makes the fluctuation range of the attitude angles of the robot and the ground reaction forces (GRFs) of the supporting legs smaller. It is proved that this control method can effectively improve the walking stability and robustness of the quadruped robot.

Torso motion control and toe trajectory generation of a trotting quadruped robot based on virtual model control

2015 ◽  
Vol 30 (4) ◽  
pp. 284-297 ◽  
Author(s):  
Guoteng Zhang ◽  
Xuewen Rong ◽  
Chai Hui ◽  
Yibin Li ◽  
Bin Li
Keyword(s):  
Motion Control ◽  
Trajectory Generation ◽  
Quadruped Robot ◽  
Virtual Model ◽  
Model Control

scholarly journals Control of trotting gait for load-carrying quadruped walking vehicle with eccentric torso

2020 ◽  
Vol 17 (4) ◽  
pp. 172988142093167
Author(s):  
Yongying Tan ◽  
Zhiqiang Chao ◽  
Huaying Li ◽  
Shousong Han ◽  
Ying Jin
Keyword(s):  
Motion Control ◽  
Control Method ◽  
Dynamic Control ◽  
Vehicle Body ◽  
Virtual Model ◽  
Gait Control ◽  
Joint Torques ◽  
Model Control ◽  
Load Carrying ◽  
Resultant Forces

Aiming at the problems of common methods in trotting gait control of a load-carrying quadruped walking vehicle, a control method, combining virtual model and centroidal dynamics, is proposed. The control of the walking vehicle is divided into two parts, meaning the motion control of the vehicle body and the motion control of the swing leg. The virtual model control method is used to work out the accelerations of the vehicle body, while the centroidal dynamics approach is used to obtain the resultant forces acting on the vehicle. Next, quadratic programming is used to distribute the resultant forces to the foot-ends of the supporting legs. Last, combining the Jacobian matrices of supporting legs, the vehicle body’s motion control is achieved. The virtual forces, acting on the swing leg foot-end, are obtained using the virtual model control method. Combining the swing leg’s Jacobian matrix, joint torques of swing leg are worked out. Simulink and Adams are adopted to jointly simulate omnidirectional trotting of the vehicle, under the condition of fixed and shifting position of eccentric weight. The effects of the virtual model and centroidal dynamics control method are compared with that of the virtual model control method. The results show that the errors of roll angle and pitch angle are reduced by 50%, 89% and 50%, 80%, respectively, as derived by virtual model and centroidal dynamic control method, under the two conditions. The proposed control algorithm is proved effective.

scholarly journals Stability Control for Electric Vehicles with Four In-Wheel-Motors Based on Sideslip Angle

2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Kun Yang ◽  
Danxiu Dong ◽  
Chao Ma ◽  
Zhaoxian Tian ◽  
Yile Chang ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Control Method ◽  
Sliding Mode ◽  
Stability Control ◽  
Torque Control ◽  
Wheel Load ◽  
Sideslip Angle ◽  
Distribution Method ◽  
Load Rate ◽  
The Stability

Tire longitudinal forces of electrics vehicle with four in-wheel-motors can be adjusted independently. This provides advantages for its stability control. In this paper, an electric vehicle with four in-wheel-motors is taken as the research object. Considering key factors such as vehicle velocity and road adhesion coefficient, the criterion of vehicle stability is studied, based on phase plane of sideslip angle and sideslip-angle rate. To solve the problem that the sideslip angle of vehicles is difficult to measure, an algorithm for estimating the sideslip angle based on extended Kalman filter is designed. The control method for vehicle yaw moment based on sliding-mode control and the distribution method for wheel driving/braking torque are proposed. The distribution method takes the minimum sum of the square for wheel load rate as the optimization objective. Based on Matlab/Simulink and Carsim, a cosimulation model for the stability control of electric vehicles with four in-wheel-motors is built. The accuracy of the proposed stability criterion, the algorithm for estimating the sideslip angle and the wheel torque control method are verified. The relevant research can provide some reference for the development of the stability control for electric vehicles with four in-wheel-motors.

Stable control of the high-speeding magnetically suspended rotor based on extended state observer and two-degree freedom internal model control for control moment gyros with serious moving-gimbal effects

2020 ◽  
Vol 42 (14) ◽  
pp. 2733-2743
Author(s):  
Jiqiang Tang ◽  
Tongkun Wei ◽  
Qichao Lv ◽  
Xu Cui
Keyword(s):  
Internal Model ◽  
Feedback Linearization ◽  
Control Method ◽  
Fast Response ◽  
State Observer ◽  
Internal Model Control ◽  
Extended State Observer ◽  
Extended State ◽  
Control Moment ◽  
Model Control

For a magnetically suspended control moment gyro (MSCMG), which is an ideal attitude actuator for its large outputting control moment and fast response, the moving-gimbal effects due to the coupling between the moving gimbal and high-speeding rotor will make the magnetically suspended rotor (MSR) unstable. To improve control precision, both the dynamic model of MSR and the feedback linearization control are done to decouple tilting motion, and poles of the system are reconfigured to reduce control error. To suppress the varying disturbance moments caused by moving-gimbal effects, an extended state observer (ESO) is originally designed to estimate and compensate them timely and accurately. To improve system robustness, a two-degree freedom internal model control (2-DOF IMC) is researched to suppress model error. Compared with existing proportional integral derivative (PID) control method, simulations done on a single gimbal MSCMG with 200 N.m.s angular momentum indicated that this presented control method with ESO and 2-DOF IMC can suppress the moving-gimbal effects more effectively and make the rotor suspension more stable.

VSC-MTDC System Integrating Offshore Wind Farms Based Optimal Distribution Method for Financial Improvement on Wind Producers

2019 ◽  
Vol 55 (3) ◽  
pp. 2232-2240 ◽  
Author(s):  
Kaiqi Sun ◽  
Ke-Jun Li ◽  
Wei-Jen Lee ◽  
Zhuo-di Wang ◽  
Weiyu Bao ◽  
...  
Keyword(s):  
Wind Farms ◽  
Offshore Wind ◽  
Optimal Distribution ◽  
Distribution Method ◽  
Offshore Wind Farms

scholarly journals Analysis and Design of an Air-Coupled DC Transformer with a Hybrid Modulation Control Method

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2570
Author(s):  
Song Xu ◽  
Wei Jiang ◽  
Seiji Hashimoto
Keyword(s):  
Control Method ◽  
Open Loop ◽  
Energy Utilization ◽  
Modulation Method ◽  
Transfer Model ◽  
Power Transfer ◽  
Analysis And Design ◽  
Hybrid Modulation ◽  
Model Control ◽  
Dc Transformer

DC micro-grid is gaining increasing attention recently due to its highly efficient energy utilization and flexible energy exchange capabilities. In this paper, an air-coupled DC–DC transformer is proposed for the interconnection between the active load and the DC microgrid. The generic problems in an air-coupled power transfer system without ferromagnetic structure are discussed. A bidirectional half-bridge topology is also proposed to suit the characteristics of the stationary load and to realize the bidirectional power transfer between the active DC load and the DC grid. A Hybrid Modulation Method (HMM) is proposed; the small signal model is derived and linear control techniques are applied to the forward power transfer control, and phase model control is applied to the reverse power transfer model. The open-loop system is simulated by PSIM to get the characteristics of the forward and reverse transfer model, and the closed system is built in the MATLAB/SIMULINK to verify the effect of the forward frequency control method and the reverse phase control method. The prototype is built with a dsPIC controller, tests are performed to evaluate the characteristics of the transformer and the power flow control of the bidirectional power transfer.

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